Every single sign, (except Cancer, because blood-red screws up the pretty rainbow effect) is the exact same color as the corresponding homestuck troll. Right down to the exact shades of blue for Libra through Sagittarius. So yeah, when the colors and symbols match (again, except for Cancer), people are going to make the connection.

Different shades of red. Cancer in homestuck is a bright crimson while Aries is a a darker, rust-colored red. Story-wise, Cancer is suppose to be wrong in the spectrum. A mutation. If he was the right color he'd have to be either that yellow or a bright lime green.